Process for making yarn from a thermoplastic strip



F. SCRAGG Aug. 10, 1965 PROCESS FOR MAKING YARN FROM A THERMOPLASTIC STRIP Filed July 25, 1963 m w m; y ffl T 5 FIG. 3.-

United States Patent 3,199,284 PRQCESS FOR MAKING YARN FRtGM A THERMOPLASTIC Slliil? Frederick Scragg, Mohberley, England, assignor to Ernest Scragg & Sons Limited, Macclesfield, England Filed July 25, 1963, Ser. N 2975M Claims priority, application Great Britain, July 26, 1962, 28,710/62 14 (Ilaiins. (Ci. 57l57) The present invention relates to textile yarns and to processes for the manufacture thereof.

It is well known that during the manufacture of a textile yarn from a plurality of relatively short fibers, such as cotton, it is necessary to draft or align the fibers into a sliver and then to twist the sliver, the twist being for the purpose of imparting strength to the sliver and binding the fibers together. Such a yarn has a relatively soft handle if the turn per inch are not excessive, which is to say if the yarn is not tightly twisted, and the softness and air-retaining properties are modified not only by the degree of twist but also by the length of the ends of the fibers which protrude from the yarn. Because of the protrusion of these ends, however, it has been found that in a loosely twisted yarn some or" the fibers tend to pull out of the yarn and to pill. Similar results occur with yarns constructed from modern synthetic filaments, and, in fact, pilling occurs more readily with such filaments since their surfaces are usually smoother than those of fibers derived from natural sources.

Attempts have been made to produce non-pilling yarns having characteristics similar to those, for example, of a spun yarn such as cotton or wool, by applying a continuous crimp to the filaments of the yarn made from a continuous synthetic material. Such yarn, however, more particularly if made by twist crimping, tends to be highly elasticized, which is to say its extension under a relatively small tensioning force is excessive, although the bulk of the yarn may be satisfactory. Thus, although pilling is, of course, prevented with such yarn, the fact that the yarn possesses a series of radially extending kinks or loops provide the disadvantage that the material tends to catch on the fingers as well as to be excessively elastic and to elongate far too readily and easily for many purposes.

It is thus an object of the present invention to provide a synthetic yarn from a thermoplastic material which will not have the extreme elongation capability of conventional twist-crimped yarn and which at the same tirne will be non-pilling.

A further object of the present invention is to provide a yarn which not only cannot be elongated excessively and will not pill, but in addition which has a bulk and feel very similar to that of natural spun yarn.

It is furthermore an object of the present invention to provide a process which enable such a yarn to be economically manufactured.

It is funthermore an object of the present invention to provide a process enabling a yarn of the above type to be continuously manufactured while also enabling the resulting yarn to have the desired properties not only with respect to the handling and non-pilling characteristics but also with respect to the siZe of the yarn itself.

With the above objects in view the invention includes, in a process for manufacturing a textile yarn, the steps of piercing a thermoplastic filament-forming strip at a plurality of closely-spaced locations distributed along the strip, and then drawing the thus-pierced strip to increase the length and reduce the width thereof while elongating the piercings thereof, and the thus-expanded strip is brodrawn strip is then transversely expanded so as to widen the piercings thereof, and the thus-expanded strip is bro ken at a plurality of portions thereof which separate ad- 3,l%,24 Patented Aug. 10, 1965 ice joining piercings so as to provide the strip with a plurality of free projecting portions, and then the thus-treated strip is twisted for the final yarn to be formed therefrom.

Also, in accordance with the present invention, there is provided a textile yarn which consists of an elongated twisted thermoplastic strip which is formed with a plurality of piercings distributed thereal-ong and which has a plurality of free projecting portions distributed along the yarn and projecting from the exterior surface thereof as well as embodied in the interior thereof.

The novel features which are considered as charactertic for the invention are et forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 illustrates a portion of a thermoplastic strip which has been slit in accordance with one of the steps of the process of the present invention;

FIG. 2 illustrates the strip of FIG. 1 after it has been drawn in accordance with a further step of the process of the present invention;

FIG. 3 shows a portion of the strip of FIG. 2 after it has been transversely expanded and broken according to further features of the present invention; and

PEG. 4 is an illustration of a portion of the yarn of the present invention.

Referring to FIG. 1, there is fragmentarily illustrated therein a strip of thermoplastic filament-forming material such as nylon, and in accordance with the invention the strip 1 has been pierced at closely-spaced locations so as tobe provided with a plurality of slits 2 in a manner similar to that used in the manufacture of expanded metal, or by the use of rotary knives. The strip 1 must be made of a material which is capable of being drawn, and inasmuch as most filament-forming materials are thermoplastic, the drawing should in the case of a thermoplastic material be carried out with the use of suitably heated drawing apparatus. However, in the case of non-thermoplastic material the drawing can be carried out without any heating of the material.

*IG. 2 shows the condition of the strip 1 after it has been drawn. It will be noted that not only has the width of this strip decreased while the length thereof has correspondingly increased, but in addition the slits 2 have become elongated and in this Way formed into the longer slits 3 while at the same time the widths of the portions 4 located between the elongated parallel longitudinally extending slits has also diminished, so that the slits are located closer together in FIG. 2 than they are in FIG. 1.

The drawing step is important for the production of a yarn according to the invention inasmuch as each individual filament of an artificial yarn has a diameter on the order of 0.0006 inch and therefore it would be extremely difiicult to pierce a sheet of material which itself has a thickness of 0.001 inch or less with a pattern of slits so closely spaced that the material without any drawing could be made into a yarn. With the use of the drawing step, however, in which the material may be extended from four to twenty times its length before drawing, depending upon the nature of the material it used for the strip and the drawing temperature, it is clear that the slits can be spaced at substantial distances from each other and a thicker material can be used for the initial slitting step, while the final dimensions of the individual filamentary structures may be of the desired order. It is to be noted, however, that the dimensions of the strips and slits shown in the drawings are illustrative only and that in fact a much greater draw is possible than that which has been shown in FIG. 2 as compared to FIG. 1.

areas-ea FIG. 3 illustrates the condition of a portion of the strip 7 panding operation inwhich the strip is pulled'transverselv so as to be transversely expanded and thus made to resemble expanded metal, as is apparent from PEG. 3. This transverse expanding operation is preferably carried out continuously, and a device similar to a tenter may be employed for this purpose, suitably modified with respect to dimensions. Thereafter, a further operation is effected, according to which some of the filamentary structures are broken as indicated at the regions 5 in FIG. 3, while other filamentary structures, as illustrated .at the regions 6 in FIG. 3, remain unbroken. Thus, it will be seen that portions of the strip which separate adjoining slots or piercings thereof are broken, as indicated at 5. This breaking of the strip'r'nay be brought about by subjecting the strip to continuous or interrupted blasts of very high pressure air from minute air jets, or by bombarding the strip with a sand blast. The particles in the blastmay be edged as the case of sand, or they may be spherical and made of metal or glass, and the piercing may be assisted by heating the particles so that severance of the filamentary structures is effected cleanly.

, Finally, the entire structure which has been treated as illustrated in FIGS. 1-3 and described above is given a continuous twist as shown in FIG. 4, the unbroken strip portions 6 having atwist applied to them while the broken projecting portionsS may project slightly from the surface of the yarn giving the yarn a hairy, soft feel. Other broken projecting portions may project inwardly and be trapped betweenthe'continuous, unbroken portions of the yarn, thus giving the yarn a certain amount of bulk.

Although it is indicated in FIGS. 1 and 2 that the piercing of the strip is carried out in a series of parallel lines, this feature is not essential. The strip'rnay be pierced with a series of holes in predetermined positions as by the use of combs with multiple needles, or by piercing at rana series of random crimps, the resulting twisted yarn then having a very high proportion of air spaces compared with its total volume.

As was indicated above the piercing of the strip can be brought about by a comb or similar structure having a large number of needle points or alternatively by a blast of particlesof metal or glass of suitable size which is directed against the material so that the particles pierce it, and these particles may be heated in order to assist the piercing of the'thermoplastic strip.

Also, the required number of strippoitions may be broken or cut by passing the drawn strip, if necessary in an extended condition, beneath a further jet of particles, the number and size of which are adjusted to break the required percentage of strip portions, or by an air jet, or even by abrasion as a result of brushing the strip. Thus, with the process of the present invention there is produced a yarn as shown on an enlarged scale in FIG. 4 havin the feel of a natural yarn while still having desirable non-pilling characteristic and also having a very low extensibility.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of textile yarns differing from the types described above.

While the invention has been illustrated and described as embodied in textile yarns and process for the manufacture thereof, it is not intended to be limited to the 7 details shown, since various modifications and structural dom,.in which case the piercing may be effected with an air jet carrying particles which pierce the material as a result of the velocity imparted to the particles by the air jet. If such pierced strips are highly drawn it will be found that the holes piercedtherethrough become elongated into slits 3 as shown in FIG. 2, and the result is a I yarn as illustrated in FIG. 4.

Preferably, all of the operations are carried out in a continuous manner, the piercing, expanding, breaking and twisting operations following one another in a single machine, although several machines located in such a way that the yarn-forming material passes continuously from one to the other may be used. Alternatively, the pierced, drawn or broken material may be wrapped on bobbins after each operation if it is found that such winding and storage is desirable, and the present invention is intended to cover both the continuous and discontinuous processes of manufacture.

Although the invention has been described in connection with a nylon strip, it is to be understood that any filament-forming material such as that known under the trade name Terylene, or polypropylene, or any cellulose-based material such as cellulose diacetate which is thermoplastic, may be employed and the process applies equally to such suitable materials. v

A relatively low twist is applied to the strip of FIG. 3 in order to form the yarn of FIG. 4, and this yarn has a natural yarn-like characteristic in that it is only slightly extensible and in that a plurality, of filamentary free end portions protrude from the surface of the yarn. In additio n, inasmuch as some of the broken ends of the yarn are folded in by the twisting of the yarn and act to hold the remaining filament portions apart, the result 'that air is trapped in the interstices of the plexus.

Before the yarn is twisted it may be heated to a point below its melting temperature under a condition of very low tension,so that each filament portion may develop.

changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current'knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics'of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

ll. A process for manufacturing a textile yarn, comprising the steps of piercing an elongated thermoplastic filament-forming strip at a plurality of relatively closelyspaced locations distributed along the strip; drawing the strip so as to, increase the length and reduce the width thereof while elongatingthe pierced portions of the strip so as to form elongated piercings which extend longitudinally of said strip; breaking a plurality of strip portions which extend between pairs of transversely spaced adjoiningelon ated piercingsto provide. the strip with 'a plurality of free projecting portions; and then twisting the strip to form a yarn therefrom. V

'2. A process for manufacturinga textile yarn, comprising the steps of forming'in an elongated thermoplastic strip of filament-forming material a plurality of'elongated parallel slits; drawing the slitted strip; extending the thus-drawn strip transversely; breaking some of the portions of the strip which extend between pairs of adjoining slits thereof; and then twisting the elongated strip.

3. A process for manufacturing a textile yarn, comprising the steps of longitudinally slitting an elongated thermoplastic filament-formingstrip with a plurality of substantially parallel slits located relatively close to each other and distributed longitudinally along the strip;

drawing the strip so as to increase its length, reduce its width, and increase the length of the slits therein; transversely expanding'the thus-drawn strip so as to form merit-forming material at a plurality of locations which are relatively closely spaced and which are distributed longitudinally along the strip; drawing the thus-pierced strip so as to increase the length and decrease the width of the strip while elongating the piercings thereof; transversely expanding the thus-drawn strip so as to widen the piercings; directing a lugh-velocity air jet against the thus-expanded strip for breaking some of the portions of the strip which separate some of the piercings from each other; and then twisting the strip.

5. A process for manufacturing a textile yarn, comprising the steps of piercing an elongated strip of thermoplastic filament-forming material at a plurality of relatively closely spaced locations distributed longitudinally along the strip; drawing the strip to increase the length and decrease the width thereof while elongating the piercings thereof; expanding the strip transversely so as to widen said piercings; directing against the strip a highvelocity air jet in which high-speed particles are suspended for breaking the strip at some of the portions which separate adjoining piercings from each other; and twistin the strip.

6. A process for manufacturing a textile yarn comprising the steps of piercing a strip of thermoplastic filazent-forrning material at a plurality of relatively closely spaced locations distributed longitudinally along the strip; drawing the stri to increase the length and de crease the width thereof While elongating the piercings thereof; expanding the strip transversely to widen the piercings; directing against the strip a jet of heated particles which break the strip at a plurality of portions which separate adjoining piercings from each other; and then twisting the strip.

7. A yarn manufacturing process comprising the steps of piercing a strip of thermoplastic filament-forming material at a plurality of relatively closely spaced locations distributed longitudinally along the strip; drawing the strip to increase the length and decrease the Width thereof while elongating the piercings thereof; transversely ex panding the strip to widen the piercings thereof; directing against the strip a jet of sand particles for breaking the strip at a plurality of portions which separate adjoining piercings from each other; and then twisting the strip to form a yarn therefrom.

8. A yarn manufacturing process comprising the steps of piercin at a plurality of relatively closely spaced locations a strip of thermoplastic filament-forming material; drawing the thus-pierced strip to increase the length and decrease the width thereof while elongating the piercings thereof; transversely expanding the thus-drawn strip for widening the piercings thereof; directing against the thusexpanded strip a jet of glass particles which break the strip at a plurality of portions which separate adjoining piercings from each other; and then twisting the thusbroken strip into a yarn.

9. A yarn manufacturing process comprising the steps of piercing a strip of thermoplastic filament-forming material at a plurality of relatively closely-spaced locations distributed longitudinally along the strip; drawing the thuspierced strip to increase the length and decrease the width thereof while elongating the piercings thereof; transversely expanding the strip to widen the piercings thereof; directing against the strip a jet of metal particles which break portions of the strip which separate adjoining piercings thereof; and then twisting the thus-broken strip.

10. A process for manufacturing a textile yarn comprising the steps of applying rotating knives against a strip of thermoplastic filament-forming material to provide in this strip a plurality of elongated slits which are relatively closely spaced and extend along the strip; drawing the strip to increase the length and decrease the width thereof while elongating the slits thereof; transversely expanding the thus-drawn strip to widen the slits thereof; breaking the strip at a plurality of portions which separate adjoining slits; and twisting the strip.

11. A textile yarn manufacturing process comprising the steps of applying needle combs to a strip of thermoplastic iilament-forming material to slit the latter; drawing the thus-slit strip to increase the length and reduce the width thereof while elongating the slits; transversely expanding the thus-drawn strip; breaking the strip at a plurality of portions thereof which separate adjoining slits; and then twisting the thus-broken strip into a yarn.

12. A textile yarn manufacturing process comprising the steps of directing a jet of high-speed particles against a strip of thermoplastic filament-forming material for piercing the latter at a plurality of relatively closelyspaced locations distributed longitudinally along the strip; drawing the thus-pierced strip to increase the length and decrease the width thereof while elongating the piercings thereof; transversely expanding the thus drawn strip to widen the piercings thereof; breaking the thus-expanded strip at portions which separate adjoining piercings from each other; and then twisting the thus-broken strip into a yarn.

13. A yarn manufacturing process comprising the steps of piercing a strip of thermoplastic filament-forming material at a plurality of closely-spaced locations distributed along the strip; drawing the thus-pierced material without increasing the temperature thereof in order to increase the length and decrease the width of the strip While elongating the piercings thereof; transversely expanding the thus-drawn strip to widen the piercings; breaking the strip at a plurality of locations which separate adjoining piercings from each other; and then twisting the thus-broken strip to form a yarn therefrom.

14. A textile yarn manufacturing process comprising the steps of piercing a strip of thermoplastic filamentforming material at a plurality of closely spaced locations distributed longitudinally along the strip; drawing the thuspierced strip at an elevated temperature to increase the length and reduce the width thereof while elongating the piercings thereof; transversely expanding the thus-drawn strip to widen the piercings thereof; breaking portions of the strip which separate adjoining piercings thereof; and then twisting the thus-broken strip into a yarn.

References tilted by the Examiner UNITED STATES PATENTS 2,336,100 12/43 Jacque 57-167 2,853,741 9/58 Costa et al 264-280 2,867,890 1/59 Baxter 57-167X 2,869,967 1/59 Breen 57-140 2,920,349 1/60 White 264- X 2,948,103 8/60 Nai 57-157 2,954,587 10/60 Rasmussen 28-12 3,001,359 9/61 Simon 57-157 3,081,519 3/63 Blades et al 57-140 FOREIGN PATENTS 864,695 4/61 Great Britain.

DONALD W. PARKER, Primary Examiner. MERVIN STEIN, Examiner. 

2. A PROCESS FOR MANUFACTURING A TEXTILE YARN, COMPRISING THE STEPS OF FORMING IN AN ELONGATED THERMOPLASTIC STRIP OF FILAMENT-FORMING MATERIAL A PLURALITY OF ELONGATED PARALLEL SLITS; DRAWING THE SLITTED STRIP; EXTENDING THE THUS-DRAWN STRIP TRANSVERSELY; BREAKING SOME OF THE PORTION OF THE STRIP WHICH EXTEND BETWEEN PAIRS OF ADJOINING SLITS THEREOF; AND THEN TWISTING THE ELONGATED STRIP. 